I wonder if economics is making war obsolete, at least for the larger countries. Waging war is just too damned expensive, even if your enemy lives in mud huts. If you're looking for the silver lining to the wars in Iraq and Afghanistan, here it is: They prove once and for all that the occupier doesn't come out ahead even by "winning."
It makes more sense to turn off the economic spigot to any country that starts to look threatening to its neighbor. Arguably, the United States is already in a war with Iran, but it takes the form of developing alternative fuels. When Iran can no longer find much of a market for its oil, it will have to start being a lot friendlier. The same goes for the United States. The next President of The United States (probably Obama) will be projecting a new humility thanks to a crippled economy.
North Korea has been defeated economically, for all practical purposes. So was the Soviet Union. Venezuela is getting less cocky as the price of oil plummets. China has become zero threat to the U.S. because of economic interests.
Terrorism is still the wild card. But the end of oil will put more of a dent in terrorism than any war could.
In the old days you could make a profit from a good war, thanks to pillaging and slavery. Those days have passed. Switzerland has one of the highest standards of living in the world.
I think the age of big war has passed.